Hallucinations in schizophrenia.

The prevalence of different types of hallucinations and their clinical correlates were examined in 117 DSM-III-R schizophrenic or schizoaffective disorder patients. Auditory hallucinations were by far the most common, followed by visual hallucinations, and then by tactile and olfactory or gustatory hallucinations. Auditory hallucinations were associated with an earlier age of first hospitalization among the schizophrenics. Global severity of the illness for schizophrenics was related to the presence of visual hallucinations, but not other types of hallucinations. Tactile and olfactory or gustatory hallucinations were strongly correlated with each other and with the severity of delusions for both schizophrenic and schizoaffective patients. The results suggest that important clinical differences exist between patients with different types of hallucinations, and that these clinical variables need to be controlled for in cross-cultural studies of hallucinations.